Although used by many professionals, the Marcinkiewicz 300 Series Trumpet mouthpieces were developed with students in mind. As players mature, their needs change. This series allows selection to the next logical cup depth, while maintaining the exact rim dimensions of the previous choice. The result is a mouthpiece that both feels good to the player and provides the desired sound instantly, without a frustrating transition.

The 300 Series Trumpet mouthpieces offer the same rim (similar to a 3C) on 15 different cup depths, graduated at .006 in. intervals, (the equivalent to the thickness of two human hairs.), from deepest (No.301) to shallowest (No.315), allowing the developing player to find optimal response from a mouthpiece with the same rim.